Description Dawson Precision® Optic (DPO) Tactical Reflex System for Holosun 507C, 508T, and 507Comp Reflex Sights! This is a Great Tactical option for Hard Use tactical environments. Adapter Plate with Black Rear Installed, .400″ Tall x .135″ Notch Width Easy to Install – Tools and Hardware Included Perfect Impact® Policy applies ONLY IF Dawson Precision® recommended front sight is used. *See Details HERE* If you have a Staccato DPO with carry height sights, you will need a front sight .135″ TALLER than your current front sight.   *Note: This item is Not Eligible for discounts or dealer pricing.